Periodic Current Oscillation Catalyzed By Manganese Oxide During The Electrolytic Manganese Process

China is the largest producer of metal electrolytic manganese. Under constant current, electrolysing manganese sulfate solution is the way to produce metal manganese. The concentration of Mn2+ reached saturation. In addition, the process of electrolysis are mobile and open, and current density are as high as 400A/cm2, with the characteristics of high ion concentration, current density, electrode potential far away from the equilibrium electrode potential. Thus, this system is a typically far from equilibrium system, which contains abundant nonlinear mechanism.Our previous study found that a large number of nonlinear behavior exsisted in the process of electrolysis, such as, periodic EO(Electrochemical oscillation) on the anode and fractal growth of dendrite on the cathode. These nonlinear phenomena will cause the energy consumption of electrolysis. Therefore, study on dynamic behavior of electrolytic manganese anode nonlinear can provide an effective way to find new ways of energy saving and emission reduction of electrolytic manganese. In this study, using the hydrothermal synthesis of manganese oxide catalytic current oscillation to study the structure and external factor of the manganese oxide, and explore the mechanism of manganese oxide catalytic current oscillation. Chemically synthesized(CS) manganese oxides replace in situ EC manganese oxides, which can provide more possibilities for the use of periodic current oscillation(PCO) to improve energy efficiency at large currents.The specific research content as follows:①Synthesize different structure of manganese oxide by hydrothermal synthesis method, and prepare Pt/Mn OX composite electrodes with different chemical structure and physical structure; using current oscillation phenomenon of cyclic voltammetry and current time curves to study the current oscillation phenomenon at anode, and shorten the latency of current oscillation greatly of the experiment. XRD and SEM characterization shows, δ-Mn O2 nanosheet structure and low manganese ion was the key factor for the formation of electrolytic manganese oscillation. Periodic current oscillation catalyzed by δ-Mn O2 nanosheets.②Mn(II) concentration and p H test indicated that loading δ-Mn O2 at the anode could catalyze the electrochemical oscillation; only in acidic or neutral environment with the presence of electrolytes can signal maintain. In fact, proper manganese oxide loading at the anode can avoid Mn(II) and other low-cost components oxidating and improve the selectivity of water oxidation. The Pt/Mn OX composite electrode as the anode current oscillations occur for power analysis shows that, from the beginning of the current oscillation to the current oscillation at the maximum amplitude of PAC/Paver, power were as high as 40%, the average value is 40% and above.③Dynamic analysis showed that the concentration of Mn O2+ and Mn OH2+ in the overburden pressure of the Mn OX layer changes with time periodically, led to periodically changes of H2O2 concentration and current. fPCO=K[H+]0.5 obtains the current oscillation frequency. Operate the experiment related to temperature at the same time, verified the rationality of the mechanism.